In recent years, hybrid vehicles in which an internal combustion engine is combined with a secondary battery as an electrical storage device and an electric motor have been vigorously developed as an environmental measure. As hybrid vehicles, there are a so-called series type and a parallel type. Among these, the series type hybrid vehicle uses the internal combustion engine for power generation and uses the electric motor for driving of the axle and regeneration.
As the series type hybrid vehicle, a hybrid automobile which controls a drive state of the internal combustion engine according to decreases in the charge amount of the secondary battery is conventionally known (for example, refer to Patent Literature 1). Such a hybrid automobile starts travelling from a state where the state of charge of the electrical storage device is higher than a control target and travels with the engine stopped until the state of charge reaches the control target. After the state of charge reaches the control target, the hybrid automobile travels using the engine and a motor generator.